1. Field of the Invention
The present invention is directed toward a synthetic rope that includes a core surrounded by a cut-resistant jacket. One embodiment of the present rope may be used for mooring off-shore oil rigs wherein the cut-resistant jacket resists the cutting action of trawling lines used in the commercial fishing industry.
2. Background Art
Deep-water off-shore platforms for oil drilling often use high-strength polyester deep-water mooring ropes to tether the platform to the ocean floor. The strength-to-weight ratio of the polyester rope is very desirable because the mooring ropes may be thousands of feet in order to reach the ocean floor. Thus, installing, transporting, moving, or otherwise maneuvering the mooring ropes proves very burdensome and dangerous if heavier mooring rope is used. As such, polyester mooring rope is very desirable for use in mooring oil platforms to the ocean floor because of its lighter weight and substantial strength.
However, while the use of polyester mooring rope is widespread throughout the off-shore oil drilling industry, an unsolved need has been identified by off-shore platform operators. Off-shore oil platforms are often located in the middle of the ocean and these platforms also share the ocean with commercial fishing vessels. Commercial fishing vessels often employ a popular method of commercial fishing called trawling. Trawling involves dragging a trawl that comprises a structure and a net being drug through the water behind one or more boats. Trawling may be performed at full-depth wherein the trawl is drug along the ocean floor or at mid-depth where the trawl is drug through the water at a depth where fish have been located. Mid-depth trawling may include selecting the depth of the trawl based upon a measured depth of fish obtained by radar or other method now known or hereafter developed.
Because a trawl may be dragged a long distance behind a fishing boat, the trawling gear behind the boat may come into contact with the off-shore platform mooring ropes as the boat(s) navigate around the platform(s). Polyester mooring ropes are often sliced or severely damaged by the trawl gear being dragged through the water when the wire rope or other rope of the trawl is dragged across one area of the mooring rope, which results in abrasion cutting similar to a slicing knife. It is difficult to determine if the mooring ropes are damaged unless the ropes are detached and brought to the surface for testing. In addition to the costs of replacing the mooring rope, the slicing or damage to one or more mooring ropes may de-stabilize the off-shore platform and/or cause it to drift slightly which may result in undesired forces or movement of the drilling casing or oil-recovery pipe. Thus, reacting to this immediate need, the inventors of the present invention developed a rope with a cut-resistant jacket that includes the weight/strength ratio desired for use for mooring the off-shore oil platforms, but is also configured to resist the cutting action of the trawl gear. Such a rope would constitute a substantial improvement to existing polyester mooring ropes.
Thus, there is a substantial need in the art for off-shore oil platform mooring ropes having both the desired strength to weight ration of polyester mooring rope, yet is configured to resist the cutting action when exposed to the dragged trawl gear.